Wood filling and finishing apparatus



Aug. 21, 1951 H. 5. MACDONALD 2,565,036

WOOD FILLING AND FINISHING APPARATUS Filed Sept. 29, 1949 GE A RING I73M0 TOR 29A LA INVENTOR. HERBERT a. MACDONALD 4 T TORNE Y Patented Aug.21, 1951 WOODFILLING' AND FINISHING APPARATUS Herbert G. Macdonald,Monrovia, Calif, assignor to Amco Development Company, Monrovia,

Califz, a partnership ApplicationSeptember 29, 1949, Serial N 0. 118,641

6 Claims.

This invention relatesto a method of and an apparatus for forcing afiller such as wax. or resin, into wood. It findslapplicationinthe-prefinishing of parquet, flooring, sheets: of plywood, or any woodmember in which they grain hasnot been filled.

Parquet flooring blocks generally are prefinrished. by a long series oftime consuming and expensive, steps. Several different methods areemployed commercially to prepare theblocks for market. Usually the blockis first coated. with a sealer. Next the open grain of the wood isfilled with a commercial filler of'silica. powder and oil. After anextended. drying period, the block is coated with shellac or otherresinous finish, or possibly with a plastic coat. Another. drying periodensues, after which-stillanother coat may beapplied. The second coatnecessitates another delay for drying. Then possibly as: a final step, acoat of wax is applied. Frequently; to hasten the'process, ovens or fansor lamps are-utilized to shorten the drying periods. Suchmulti-stepoperations are expensive. They raise the cost of prefinishedflooring and other materials to which they are applied.

Through the application of my invention, parquet flooring blocks,plywood, ordinary boards, and in fact any woodmember may be pro-finishedin a single rapid operation. Moreover,- the quality of the finishedproduct frequently is improved, in that a deeper penetration of the woodwith the filler and a more uniform polish or gloss are obtained, the netresult being amore durable. and satisfactory finish.

Briefly, my method of filling the surface of a wood member with afusible solid comprises the steps of applying the solid in substantiallyfused condition to a curved surface, rotating the coated curvedsurfaceagainst the surface of the wood to be coated and simultaneously pressingthe two surfaces together, whereby the solid is transferred to the woodsurface. In myv preferred op eraticn, heat generated by the friction ofwood and curved surface. heats the latter, and the solid filler ispressed against the curved surface and melted or at least softenedtoproduce thefilm.

Generally speaking, the apparatus of my. in.- vention is acounter-rotating drum whichbears upon the wood member and which forcesa. filler such as wax or resin'into the surface of thewood; the fillerbeing applied as a molten or semi.- molten film to the drum. The drumnot only forces the filler into the grain of the, wood but in addition,polishes the surface to a substantial degree. If it is desired to have afinished product with a high gloss, a polishing roller may be dis.-posed to turn counter to the Wood following the application of thefiller. To obtain a product with a maximum gloss, a polishing rollerhaving a surface with a high coeificient of friction with respect to thewood member should be employed, e. g. steel wool.

Satisfactory results are obtained by merely applying the waxy orresinous filler in accordance with my invention. However, I prefer topretreat the wood with a liquid, such as a lacquer containing apolymerizable resin, prior to introducing the wax. This-lacquerispainted on and allowed to dry. Ithardens the wood and emphafsizes;grainand naturalcolor.

Ina presently preferred-form, the, apparatus of the invention comprisesa table, means for moving a wood. member to be treated over the table, adrum rotatably mounted above the table to bear. on the surface of themember and generate heat by friction between the drum and the member;and. means for holding a. fusible filler suchas wax against the drum sothat the heat developedin the drum will melt or soften it and produce afilmon the drum to be transferred to the surface of the wood. The tableis not essential. Any member, such as another drum, which supports thewood under the pressure of the applicator; drum, will suifice.Furthermore, it is not necessary that the wood member. movebeneath thedrum. For instance,- the wood member could. travel along. an overheadtrack with the applicator; drum bearing upon the under. surface of; thewood member.

These and other aspects of myinvention willbe understood more thoroughlyin the light of the following; detailed. description taken inconjunction withlthe accompanying drawings in which:

Fig. 1 is a longitudinal elevation, partly in section, of oneform of theapparatus of the inven: tion, particularly adapted to the pie-finishingof parquet flooring blocks;

Fig, 2 isa plan view of. the apparatus of Big. 1; and

Fig. 3. is a longitudinal elevation, partly insection, of armodifiedformof the apparatus of; Figs. 1 and 2.

Referring toE'igs. 1 and 2, rectangular. parquet flooring blocksm'resting as a stack. in a rack H arepulled one by. one from the bottomof the stack ontoa conventional endless belt feeder I2 driven by aroller It. The belt feeder has trans? verse lugs l4 spacedfrom:eachother byslightly morethan. tbelength of. the blocks, scthat theblocks drop: between them onto thebelt and are pushed along by the lugs.The blocks pass, one after another with their edges abutting, onto andalong a table 15, the blocks being moved along the table by a, pair ofdrive rolls l6, ll one above the line of travel of the blocks, the otherbelow. The lower roll is driven clockwise and the upper counterclockwise(as viewed in Fig. 1) by conventional means, such as a motor HA andgearing NB. The two rolls grip the blocks and force them to travel as atrain along the table.

The train of blocks moving along the table is prevented from bucklingupward by horizontal guide plates l3, 19 disposed just above the blocksalong the path of travel, but with sufficient clearance to permit easymovement.

An applicator drum 2!) is disposed above the table between the guideplates with its shaft 21 perpendicular to the direction of travel of theblocks and parallel to the axis of the drive rolls. The shaft is rigidlymounted with respect to the table and spaced above it by a distancewhich assures that the drum will exert substantial pressure on theblocks as they pass underneath it. The drum is driven counter to thedirection of travel of the blocks (clockwise as viewed in Fig. 1) byconventional means such as a motor 26A. The applicator drum has acovering 22 (such as sandpaper which has been worn down substantially)with a high coefficient of friction with respect to the blocks and suchthat it will not stretch substantially so as to free itself from thedrum.

A stick 23 of hard wax having a softening point of about 190 F., ismounted vertically in a holder 24 directly above the drum so that itslower end bears against the drum cover. The stick is free to slidedownward in the holder as it is consumed, and the downward movement isfurthered by a weight 25 which rides in the holder on top of the stick.The holder is attached to a slider 26 which is moved back and forth in atrack 21 (having a T-shaped groove in which the slider fits) parallel tothe shaft of the drum, this movement being attained by a wrist pin 28attached to the holder and at its other end to a crank mechanism 29. Theaxis of rotation of the crank is perpendicular to the direction ofmovement of the slider, and the throw of the crank is such that thestick is oscillated across the full length of the drum or at leastacross that portion of the length which comes in contact with theblocks. The crank is positively driven by conventional means, such as amotor 29A.

A polishing drum 30 is mounted above the table parallel to theapplicator drum but beyond the second guide plate. It too bears upon thetrain of blocks forcibly and is rotated counter to the blocks byconventional driving means such as a motor 30A. A cover 31 of polishingmaterial, such as steel wool, is placed on the polishing drum.

Heat is generated by the friction between the surface of the applicatordrum and that of the block train. Part of this heat is stored in theapplicator drum itself so that the temperature of its cover, as thelatter comes in contact with the wax stick, is sufficient to melt thelatter slowly and thus cause it to spread as a film on the cover. Thisfilm is carried downward and squeezed into the blocks of the train asthey pass under the applicator drum, thus filling their surfaces.

Ordinarily, the heat generated and stored in the applicator drum will besufficient to melt the wax and apply it to the drum in a film ofadequate thickness for proper filling of the wood. If however, themelting point of the wax is very high, or the friction between drum andblock train insufficient, or the speed of travel of the block train veryfast, it may be desirable to supply additional heat to the drum, forexample with an auxiliary electrical heater 32 disposed on the inside ofthe drum in good heat conductive relationship therewith.

In order that the wax be melted to as large a. degree as possible by theheat of friction developed at the contact of applicator drum and blocktrain, the drum itself should be of material having a relatively highspecific heat, say iron or copper, and of sufficient mass to affordadequate heat storage.

The apparatus of Fig. 3 is in general similar to that of Fig. 1, likeparts being designated by like reference characters. In the apparatus ofFig. 3, however, the conveyor belt [2 extends along the table andcarries the block train under the treatment drums. Consequently, thedrive rolls are omitted. Because the blocks of the train are held apartby the lugs It on the conveyor belt, there is substantially no tendencyfor the blocks to buckle upward. Hence the guide plates are omitted. Theonly other difference between the apparatus of Figs. 1 and 2 and that ofFig. 3 is the addition of another polishing roller 33 which like thefirst is positively driven counter to the direction of movement of theblock train.

If desired, the table in the apparatus of Figs. 1 and 2 and that of Fig.3 may be replaced by a train of idler rollers of relatively smalldiameter and spaced close together. These rollers are rotatable on axesperpendicular to the direction of travel of the block train and supportthe train without requiring so much power tomove the train of blocksunder the series of rollers.

In some operations, it may be desirable to provide another applicatordrum or drums to give a heavier coat of wax or resin. A brush or seriesof brushes may be substituted for or used with the polishing rollersdescribed previously.

I claim:

1. In apparatus for filling a wood surface with a fusible solid, thecombination which comprises a support, means for moving a wood memberthe surface of which is to be filled over the support, a drum rotatablymounted adjacent the support to bear on the surface and generate heat byfriction between the surface of the wood and that of the drum, means forpower driving the drum counter to the movement of the wood member on thesupport, and means for holding the fusible solid against the drum sothat the heat developed in the drum will melt the solid and produce afilm on the drum to be transferred to the surface of the wood.

2. In apparatus for filling a wood surface with a fusible solid, thecombination which comprises a table, means for moving a wood member thesurface of which is to be filled along the table, a drum rotatablymounted above the table to bear on the surface and generate heat byfriction between the wood and the drum, means for power driving the drumcounter to the direction of movement of the wood member, means forholding the fusible solid against the drum so that the heat developed inthe drum will melt the solid and produce a film on the drum to betransferred to the surface of the wood, and means for oscillating thefusibl solid along but in contact with the drum.

3. In apparatus for filling a wood surface with a fusible solid, thecombination which comprises a table, mean for moving a wood member thesurface of which is to be filled over the table, a drum rotatablymounted above the table to bear on said surface and generate heat byfriction between the surface of th wood and that of the drum, means forpower driving the drum counter to the direction of movement of the wood,means for holding the fusible solid against the drum so that the heatdeveloped in the drum will melt the solid and produce a film on the drumto be transferred to the surface of the wood, and a polishing rollerspaced beyond the drum in the direction of travel of the wood member ina position to bear upon the wood member.

4. Apparatus according to claim 3 provided with means for driving thepolishing roller counter to the direction of travel of the Wood member.

5. In apparatus for filling a wood surface with a fusible solid, thecombination which comprises means for moving in one direction a Woodmember the surface of which is to be filled, an endless revolvablemember movable against the surface of the wood counter to its directionof movement to generate heat and having substantial capacity for storingthe heat thus generated, means for holding a fusible solid against themember so that the heat stored in the member will melt the solid andproduce a film thereon, and means for pressing the endless membercarrying the film against the wood.

6. Apparatus according to claim 5 in which the endless member is a drum.n,

HERBERT G. MACDONALD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,308,589 Davis Jan. 19, 19432,341,161 Partee et al. Feb. 8, 1944 2,468,266 Lyons et al Apr. 26, 1949

